oqpsk_10.m

oqpsk信号

clear all;
%function y=QAM_4(fs,bits)
bits=randint(800,1,2);
fs=8e7;
rb=1e6;
fc=1e7;
fa=1e5;
bits2(1)=1;
for i=1:400
    ba(i)=bits(2*i-1);
    bb(i)=bits(2*i);
end
for i=1:400
    bits1(2*i-1)=ba(i);
    bits1(2*i)=ba(i);
    bits2(2*i)=bb(i);
    bits2(2*i+1)=bb(i);
end
bits2=bits2(1:800);

nb=length(bits1);
ns=ceil(nb/2);
IR=[-1 1];
t=[0:79]; 
for s=1:800
    R=IR(bits1(s)+1);
    I=IR(bits2(s)+1);
    r(s)=R+j*I;
    y1(s)=abs(r(s));  
end

[ys,ts] = rcosine(2*rb,fs,'fir/sqrt',1.0);
[yc,tc] = rcosflt(r,2*rb,fs,'filter',ys);
yc=abs(yc(81:32080));
%nb=length(yc1);
%ns=ceil(nb/2);
for s=1:400
    for t=1:80
      y((s-1)*80+t)= yc((s-1)*80+t)*cos(2*pi*fc*t/fs+angle(r(s)));
    end
end

signal=awgn( y,20,'measured',[],'db');  
%figure;
%plot(r(20:40:32000),'.');
%axis([-2 2 -2 2]);
%Y=fft(y);
%ts=(0:length(Y)-1)*fc/length(Y);
%figure;
%plot(ts,abs(Y));
% semilogy(ts,abs(Y));
% axis([1 9e4 1 1e4]);
long=8;